//
// Created by Administrator on 2020/6/19.
//
#include "iostream"
#include "string.h"
#include "cmath"

using namespace std;


void exercise1();
void exercise2();
void exercise3();
void exercise4();
void exercise5();


int main() {

    cout << "hello world !!!" << endl;

//    exercise1();      // 打印菱形
//    exercise2();        // 普通打印
    exercise3();

    return 0;
}



